Interface Defects Tuning in Polymer-Perovskite Phototransistors for Visual Synapse and Adaptation Functions

Artificial sensory nerves can simulate the functions of visual perception and information processing of the human brain, which is indispensable for the immediate visualization of the environment and awareness requisite to avoid the potential harm. However, it still remains a long-standing challenge to integrate recognition learning with real-time processing function in a single device. Herein, an interface defects-tuning strategy is proposed for developing a novel bi-functional phototransistor. Benefiting from the tuned polymer-perovskite layer-heterointerface defects, the photogenerated charge trapping and de-trapping capacities are significantly improved, thereby facilitating the photogenerated carrier separation and injection. The prepared organic-inorganic hybrid phototransistors can perfectly mimic the human visual synaptic behaviors with a quick response speed (<35 ms, far below that of human eyes to incident light (225 ms)). More importantly, the phototransistor exhibited obvious visual adaptation toward wide-ranging light stimuli, and realized unique desensitization to simulate the self-protection behavior of the human visual systems. Specifically, the adaptation timescales of the device under dim and high light conditions are superior to bio-systems (<2 min). Consequently, the reported strategy for the preparation of bi-functional phototransistors provides a brand-new perspective for next-generation artificial nervous systems.

Automated summary

This study proposes an interface defects-tuning strategy for developing a novel bi-functional phototransistor. By tuning the interface defects, the separation and injection of photogenerated carriers are significantly improved. The prepared organic-inorganic hybrid phototransistors can mimic human visual synaptic behaviors and exhibit obvious adaptation to different light stimuli.